draft-ietf-opsec-dhcpv6-shield-02.txt   draft-ietf-opsec-dhcpv6-shield-03.txt 
opsec F. Gont opsec F. Gont
Internet-Draft SI6 Networks / UTN-FRH Internet-Draft SI6 Networks / UTN-FRH
Intended status: Best Current Practice W. Liu Intended status: BCP W. Liu
Expires: August 8, 2014 Huawei Technologies Expires: December 7, 2014 Huawei Technologies
G. Van de Velde G. Van de Velde
Cisco Systems Cisco Systems
February 4, 2014 June 5, 2014
DHCPv6-Shield: Protecting Against Rogue DHCPv6 Servers DHCPv6-Shield: Protecting Against Rogue DHCPv6 Servers
draft-ietf-opsec-dhcpv6-shield-02 draft-ietf-opsec-dhcpv6-shield-03
Abstract Abstract
This document specifies a mechanism for protecting hosts connected to This document specifies a mechanism for protecting hosts connected to
a broadcast network against rogue DHCPv6 servers. The aforementioned a switched network against rogue DHCPv6 servers. The aforementioned
mechanism is based on DHCPv6 packet-filtering at the layer-2 device mechanism is based on DHCPv6 packet-filtering at the layer-2 device
at which the packets are received. The aforementioned mechanism has at which the packets are received. The aforementioned mechanism has
been widely deployed in IPv4 networks ('DHCP snooping'), and hence it been widely deployed in IPv4 networks ('DHCP snooping'), and hence it
is desirable that similar functionality be provided for IPv6 is desirable that similar functionality be provided for IPv6
networks. networks.
Status of This Memo Status of this Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 8, 2014. This Internet-Draft will expire on December 7, 2014.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
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to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 4
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. DHCPv6-Shield Configuration . . . . . . . . . . . . . . . . . 4 4. DHCPv6-Shield Configuration . . . . . . . . . . . . . . . . . 7
5. DHCPv6-Shield Implementation Advice . . . . . . . . . . . . . 4 5. DHCPv6-Shield Implementation Advice . . . . . . . . . . . . . 8
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
7. Security Considerations . . . . . . . . . . . . . . . . . . . 6 7. Security Considerations . . . . . . . . . . . . . . . . . . . 12
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 13
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
9.1. Normative References . . . . . . . . . . . . . . . . . . 7 9.1. Normative References . . . . . . . . . . . . . . . . . . . 14
9.2. Informative References . . . . . . . . . . . . . . . . . 8 9.2. Informative References . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16
1. Introduction 1. Introduction
This document specifies a mechanism for protecting hosts connected to This document specifies a mechanism for protecting hosts connected to
a broadcast network against rogue DHCPv6 servers [RFC3315]. This a switched network against rogue DHCPv6 servers [RFC3315]. This
mechanism is analogous to the RA-Guard mechanism [RFC6104] [RFC6105] mechanism is analogous to the RA-Guard mechanism [RFC6104] [RFC6105]
[I-D.ietf-v6ops-ra-guard-implementation] intended for protection [RFC7113] intended for protection against rogue Router Advertisement
against rogue Router Advertisement [RFC4861] messages. [RFC4861] messages.
The basic concept behind DHCPv6-Shield is that a layer-2 device The basic concept behind DHCPv6-Shield is that a layer-2 device
filters DHCPv6 messages meant to DHCPv6 clients (henceforth filters DHCPv6 messages meant to DHCPv6 clients (henceforth "DHCPv6-
"DHCPv6-server messages"), according to a number of different server messages"), according to a number of different criteria. The
criteria. The most basic filtering criterion is that DHCPv6-server most basic filtering criterion is that DHCPv6-server messages are
messages are discarded by the layer-2 device unless they are received discarded by the layer-2 device unless they are received on a
on a specified port of the layer-2 device. specific ports of the layer-2 device.
Before the DCHPv6-Shield device is deployed, the administrator Before the DCHPv6-Shield device is deployed, the administrator
specifies the layer-2 port(s) on which DHCPv6-server messages are to specifies the layer-2 port(s) on which DHCPv6-server messages are to
be allowed. Only those ports to which a DHCPv6 server is to be be allowed. Only those ports to which a DHCPv6 server or relay is to
connected should be specified as such. Once deployed, the be connected should be specified as such. Once deployed, the DHCPv6-
DHCPv6-Shield device inspects received packets, and allows (i.e. Shield device inspects received packets, and allows (i.e. passes)
passes) DHCPv6-server messages only if they are received on layer-2 DHCPv6-server messages only if they are received on layer-2 ports
ports that have been explicitly configured for such purpose. that have been explicitly configured for such purpose.
2. Requirements Language 2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
3. Terminology 3. Terminology
DHCPv6 Shield device:
A layer-2 device (typically a layer-2 switch) that enforces the
filtering policy specified in this document.
For the purposes of this document, the terms Extension Header, Header For the purposes of this document, the terms Extension Header, Header
Chain, First Fragment, and Upper-layer Header are used as follows Chain, First Fragment, and Upper-layer Header are used as follows
[RFC7112]: [RFC7112]:
Extension Header: Extension Header:
Extension Headers are defined in Section 4 of [RFC2460]. As a Extension Headers are defined in Section 4 of [RFC2460]. As a
result of [RFC7045], [IANA-PROTO] provides a list of assigned result of [RFC7045], [IANA-PROTO] provides a list of assigned
Internet Protocol Numbers and designates which of those protocol Internet Protocol Numbers and designates which of those protocol
numbers also represent extension headers. numbers also represent extension headers.
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chain. In a simple example, if the upper-layer header is a TCP chain. In a simple example, if the upper-layer header is a TCP
header, the TCP payload is not part of the header chain. In a header, the TCP payload is not part of the header chain. In a
more complex example, if the upper-layer header is an ESP header, more complex example, if the upper-layer header is an ESP header,
neither the payload data, nor any of the fields that follow the neither the payload data, nor any of the fields that follow the
payload data in the ESP header are part of the header chain. payload data in the ESP header are part of the header chain.
4. DHCPv6-Shield Configuration 4. DHCPv6-Shield Configuration
Before being deployed for production, the DHCPv6-Shield device MUST Before being deployed for production, the DHCPv6-Shield device MUST
be explicitly configured with respect to which layer-2 ports are be explicitly configured with respect to which layer-2 ports are
allowed to send DHCPv6 packets to DHCPv6 clients (i.e. DHCPv6-server allowed to send DHCPv6 packets to DHCPv6 clients (i.e. DHCPv6-server
messages). Only those layer-2 ports explicitly configured for such messages). Only those layer-2 ports explicitly configured for such
purpose will be allowed to send DHCPv6 packets to DHCPv6 clients. purpose will be allowed to send DHCPv6 packets to DHCPv6 clients.
5. DHCPv6-Shield Implementation Advice 5. DHCPv6-Shield Implementation Advice
The following filtering rules MUST be enforced as part of a The following filtering rules MUST be enforced as part of a DHCPv6-
DHCPv6-Shield implementation on those ports that are not allowed to Shield implementation on those ports that are not allowed to send
send DHCPv6 packets to DHCPv6 clients: DHCPv6 packets to DHCPv6 clients:
1. DHCPv6-Shield MUST parse the IPv6 entire header chain present in 1. DHCPv6-Shield MUST parse the IPv6 entire header chain present in
the packet, to identify whether it is a DHCPv6 packet meant for a the packet, to identify whether it is a DHCPv6 packet meant for a
DHCPv6 client (i.e., a DHCPv6-server message). DHCPv6 client (i.e., a DHCPv6-server message).
RATIONALE: DHCPv6-Shield implementations MUST NOT enforce a RATIONALE: DHCPv6-Shield implementations MUST NOT enforce a
limit on the number of bytes they can inspect (starting from limit on the number of bytes they can inspect (starting from
the beginning of the IPv6 packet), since this could introduce the beginning of the IPv6 packet), since this could introduce
false-positives: legitimate packets could be dropped simply false-positives: legitimate packets could be dropped simply
because the DHCPv6-Shield device does not parse the entire because the DHCPv6-Shield device does not parse the entire
IPv6 header chain present in the packet. An implementation IPv6 header chain present in the packet. An implementation
that has such an implementation-specific limit MUST NOT claim that has such an implementation-specific limit MUST NOT claim
compliance with this specification, and MUST pass the packet compliance with this specification.
when such implementation-specific limit is reached.
2. When parsing the IPv6 header chain, if the packet is a first- 2. When parsing the IPv6 header chain, if the packet is a first-
fragment (i.e., a packet containing a Fragment Header with the fragment (i.e., a packet containing a Fragment Header with the
Fragment Offset set to 0) and it fails to contain the entire IPv6 Fragment Offset set to 0) and it fails to contain the entire IPv6
header chain (i.e., all the headers starting from the IPv6 header header chain (i.e., all the headers starting from the IPv6 header
up to, and including, the upper-layer header), DHCPv6-Shield MUST up to, and including, the upper-layer header), DHCPv6-Shield MUST
drop the packet, and SHOULD log the packet drop event in an drop the packet, and SHOULD log the packet drop event in an
implementation-specific manner as a security fault. implementation-specific manner as a security fault.
RATIONALE: [RFC7112] specifies that the first-fragment (i.e., RATIONALE: [RFC7112] specifies that the first-fragment (i.e.,
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a Fragment Offset of 0 (non-first fragments can be safely a Fragment Offset of 0 (non-first fragments can be safely
passed, since they will never reassemble into a complete passed, since they will never reassemble into a complete
datagram if they are part of a DHCPv6 packet meant for a datagram if they are part of a DHCPv6 packet meant for a
DHCPv6 client received on a port where such packets are not DHCPv6 client received on a port where such packets are not
allowed). allowed).
3. When parsing the IPv6 header chain, if the packet is identified 3. When parsing the IPv6 header chain, if the packet is identified
to be a DHCPv6 packet meant for a DHCPv6 client or the packet to be a DHCPv6 packet meant for a DHCPv6 client or the packet
contains an unrecognized Next Header value, DHCPv6-Shield MUST contains an unrecognized Next Header value, DHCPv6-Shield MUST
drop the packet, and SHOULD log the packet drop event in an drop the packet, and SHOULD log the packet drop event in an
implementation-specific manner as a security fault. implementation-specific manner as a security alert. DHCPv6-
DHCPv6-Shield MUST provide a configuration knob that controls Shield MUST provide a configuration knob that controls whether
whether packets with unrecognized Next Header values are dropped; packets with unrecognized Next Header values are dropped; this
this configuration knob MUST default to "drop". configuration knob MUST default to "drop".
RATIONALE: [RFC7045] requires that nodes be configurable with RATIONALE: [RFC7045] requires that nodes be configurable with
respect to whether packets with unrecognized headers are respect to whether packets with unrecognized headers are
forwarded, and allows the default behavior to be that such forwarded, and allows the default behavior to be that such
packets be dropped. packets be dropped.
4. In all other cases, DHCPv6-Shield MUST pass the packet as usual. 4. In all other cases, DHCPv6-Shield MUST pass the packet as usual.
NOTE: For the purpose of enforcing the DHCPv6-Shield filtering NOTE: For the purpose of enforcing the DHCPv6-Shield filtering
policy, an ESP header [RFC4303] should be considered to be an policy, an ESP header [RFC4303] should be considered to be an
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If a packet is dropped due to this filtering policy, then the packet If a packet is dropped due to this filtering policy, then the packet
drop event SHOULD be logged in an implementation-specific manner as a drop event SHOULD be logged in an implementation-specific manner as a
security fault. The logging mechanism SHOULD include a drop counter security fault. The logging mechanism SHOULD include a drop counter
dedicated to DHCPv6-Shield packet drops. dedicated to DHCPv6-Shield packet drops.
In order to protect current end-node IPv6 implementations, Rule #2 In order to protect current end-node IPv6 implementations, Rule #2
has been defined as a default rule to drop packets that cannot be has been defined as a default rule to drop packets that cannot be
positively identified as not being DHCPv6-server packets (because the positively identified as not being DHCPv6-server packets (because the
packet is a fragment that fails to include the entire IPv6 header packet is a fragment that fails to include the entire IPv6 header
chain). This means that, at least in theory, DHCPv6-Shield could chain). This means that, at least in theory, DHCPv6-Shield could
result in false-positive blocking of some legitimate (non result in false-positive blocking of some legitimate (non DHCPv6-
DHCPv6-server) packets. However, as noted in [RFC7112], IPv6 packets server) packets. However, as noted in [RFC7112], IPv6 packets that
that fail to include the entire IPv6 header chain are virtually fail to include the entire IPv6 header chain are virtually impossible
impossible to police with state-less filters and firewalls, and hence to police with state-less filters and firewalls, and hence are
are unlikely to survive in real networks. [RFC7112] requires that unlikely to survive in real networks. [RFC7112] requires that hosts
hosts employing fragmentation include the entire IPv6 header chain in employing fragmentation include the entire IPv6 header chain in the
the first fragment (the fragment with the Fragment Offset set to 0), first fragment (the fragment with the Fragment Offset set to 0), thus
thus eliminating the aforementioned false positives. eliminating the aforementioned false positives.
The aforementioned filtering rules implicitly handle the case of The aforementioned filtering rules implicitly handle the case of
fragmented packets: if the DHCPv6-Shield device fails to identify the fragmented packets: if the DHCPv6-Shield device fails to identify the
upper-layer protocol as a result of the use of fragmentation, the upper-layer protocol as a result of the use of fragmentation, the
corresponding packets would be dropped. corresponding packets would be dropped.
Finally, we note that IPv6 implementations that allow overlapping Finally, we note that IPv6 implementations that allow overlapping
fragments (i.e. that do not comply with [RFC5722]) might still be fragments (i.e. that do not comply with [RFC5722]) might still be
subject of DHCPv6-based attacks. However, a recent assessment of subject of DHCPv6-based attacks. However, a recent assessment of
IPv6 implementations [SI6-FRAG] with respect to their fragment IPv6 implementations [SI6-FRAG] with respect to their fragment
reassembly policy seems to indicate that most current implementations reassembly policy seems to indicate that most current implementations
comply with [RFC5722]. comply with [RFC5722].
6. IANA Considerations 6. IANA Considerations
This document has no actions for IANA. This document has no actions for IANA.
7. Security Considerations 7. Security Considerations
The mechanism specified in this document can be used to mitigate The mechanism specified in this document can be used to mitigate
DHCPv6-based attacks. Attack vectors based on other messages (such DHCPv6-based attacks against hosts. Attack vectors based on other
as ICMPv6 Router Advertisements) are out of the scope of this messages meant for network configuration (such as ICMPv6 Router
document. Advertisements) are out of the scope of this document. Additionally,
the mechanism specified in this document does not mitigate attacks
against DHCPv6 servers (e.g., DoS).
If deployed in layer-2 domain with several cascading switches, there
will be an ingress port on the host's local switch which will need to
be enabled for receiving DHCPv6-server messages. However, this local
switch will be reliant on the upstream devices to have filtered out
rogue DHCPv6-server messages, as the local switch has no way of
determining which upstream DHCP-server messages are valid.
Therefore, in order to be effective DHCPv6 Shield should be deployed
and enabled on all layer-2 switches of a given layer-2 domain.
As noted in Section 5, IPv6 implementations that allow overlapping As noted in Section 5, IPv6 implementations that allow overlapping
fragments (i.e. that do not comply with [RFC5722]) might still be fragments (i.e. that do not comply with [RFC5722]) might still be
subject of DHCPv6-based attacks. However, most current subject of DHCPv6-based attacks. However, most current
implementations seem to comply with [RFC5722], and hence forbid IPv6 implementations seem to comply with [RFC5722], and hence forbid IPv6
overlapping fragments. overlapping fragments.
We note that if an attacker sends a fragmented DHCPv6 packet on a We note that if an attacker sends a fragmented DHCPv6 packet on a
port not allowed to send such packets, the first-fragment would be port not allowed to send such packets, the first-fragment would be
dropped, and the rest of the fragments would be passed. This means dropped, and the rest of the fragments would be passed. This means
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fragment reassembly buffer, this could lead to a Denial of Service fragment reassembly buffer, this could lead to a Denial of Service
(DoS). However, this does not really introduce a new attack vector, (DoS). However, this does not really introduce a new attack vector,
since an attacker could always perform the same attack by sending since an attacker could always perform the same attack by sending
forged fragmented datagram in which at least one of the fragments is forged fragmented datagram in which at least one of the fragments is
missing. [CPNI-IPv6] discusses some resource management strategies missing. [CPNI-IPv6] discusses some resource management strategies
that could be implemented for the fragment reassembly buffer. that could be implemented for the fragment reassembly buffer.
8. Acknowledgements 8. Acknowledgements
The authors would like to thank (in alphabetical order) Jean-Michel The authors would like to thank (in alphabetical order) Jean-Michel
Combes, Juergen Schoenwaelder, and Mark Smith, for providing valuable Combes, Juergen Schoenwaelder, Crsten Schmoll, Robert Sleigh, Mark
comments on earlier versions of this document. Smith, and Eric Vyncke, for providing valuable comments on earlier
versions of this document.
Section 3 of this document was borrowed from [RFC7112], authored by Part of Section 3 of this document was borrowed from [RFC7112],
Fernando Gont, Vishwas Manral, and Ron Bonica. authored by Fernando Gont, Vishwas Manral, and Ron Bonica.
This document is heavily based on the document This document is heavily based on the document [RFC7113] authored by
[I-D.ietf-v6ops-ra-guard-implementation] authored by Fernando Gont. Fernando Gont. Thus, the authors would like to thank Ran Atkinson,
Thus, the authors would like to thank Ran Atkinson, Karl Auer, Robert Karl Auer, Robert Downie, Washam Fan, David Farmer, Mike Heard, Marc
Downie, Washam Fan, David Farmer, Mike Heard, Marc Heuse, Nick Heuse, Nick Hilliard, Ray Hunter, Joel Jaeggli, Simon Perreault,
Hilliard, Ray Hunter, Joel Jaeggli, Simon Perreault, Arturo Servin, Arturo Servin, Gunter van de Velde, James Woodyatt, and Bjoern A.
Gunter van de Velde, James Woodyatt, and Bjoern A. Zeeb, for Zeeb, for providing valuable comments on [RFC7113], on which this
providing valuable comments on document is based.
[I-D.ietf-v6ops-ra-guard-implementation], on which this document is
based.
9. References 9. References
9.1. Normative References 9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 2460, December 1998. (IPv6) Specification", RFC 2460, December 1998.
[RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
and M. Carney, "Dynamic Host Configuration Protocol for and M. Carney, "Dynamic Host Configuration Protocol for
IPv6 (DHCPv6)", RFC 3315, July 2003. IPv6 (DHCPv6)", RFC 3315, July 2003.
[RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)", RFC [RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)",
4303, December 2005. RFC 4303, December 2005.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
September 2007. September 2007.
[RFC5722] Krishnan, S., "Handling of Overlapping IPv6 Fragments", [RFC5722] Krishnan, S., "Handling of Overlapping IPv6 Fragments",
RFC 5722, December 2009. RFC 5722, December 2009.
[RFC7112] Gont, F., Manral, V., and R. Bonica, "Implications of [RFC7112] Gont, F., Manral, V., and R. Bonica, "Implications of
Oversized IPv6 Header Chains", RFC 7112, January 2014. Oversized IPv6 Header Chains", RFC 7112, January 2014.
skipping to change at page 8, line 23 skipping to change at page 14, line 44
9.2. Informative References 9.2. Informative References
[RFC6104] Chown, T. and S. Venaas, "Rogue IPv6 Router Advertisement [RFC6104] Chown, T. and S. Venaas, "Rogue IPv6 Router Advertisement
Problem Statement", RFC 6104, February 2011. Problem Statement", RFC 6104, February 2011.
[RFC6105] Levy-Abegnoli, E., Van de Velde, G., Popoviciu, C., and J. [RFC6105] Levy-Abegnoli, E., Van de Velde, G., Popoviciu, C., and J.
Mohacsi, "IPv6 Router Advertisement Guard", RFC 6105, Mohacsi, "IPv6 Router Advertisement Guard", RFC 6105,
February 2011. February 2011.
[I-D.ietf-v6ops-ra-guard-implementation] [RFC7113] Gont, F., "Implementation Advice for IPv6 Router
Gont, F., "Implementation Advice for IPv6 Router Advertisement Guard (RA-Guard)", RFC 7113, February 2014.
Advertisement Guard (RA-Guard)", draft-ietf-v6ops-ra-
guard-implementation-07 (work in progress), November 2012.
[IANA-PROTO] [IANA-PROTO]
Internet Assigned Numbers Authority, "Protocol Numbers", Internet Assigned Numbers Authority, "Protocol Numbers",
February 2013, <http://www.iana.org/assignments/ February 2013, <http://www.iana.org/assignments/
protocol-numbers/protocol-numbers.txt>. protocol-numbers/protocol-numbers.txt>.
[SI6-FRAG] [SI6-FRAG]
SI6 Networks, "IPv6 NIDS evasion and improvements in IPv6 SI6 Networks, "IPv6 NIDS evasion and improvements in IPv6
fragmentation/reassembly", 2012, fragmentation/reassembly", 2012, <http://
<http://blog.si6networks.com/2012/02/ blog.si6networks.com/2012/02/
ipv6-nids-evasion-and-improvements-in.html>. ipv6-nids-evasion-and-improvements-in.html>.
[CPNI-IPv6] [CPNI-IPv6]
Gont, F., "Security Assessment of the Internet Protocol Gont, F., "Security Assessment of the Internet Protocol
version 6 (IPv6)", UK Centre for the Protection of version 6 (IPv6)", UK Centre for the Protection of
National Infrastructure, (available on request). National Infrastructure, (available on request).
Authors' Addresses Authors' Addresses
Fernando Gont Fernando Gont
SI6 Networks / UTN-FRH SI6 Networks / UTN-FRH
Evaristo Carriego 2644 Evaristo Carriego 2644
Haedo, Provincia de Buenos Aires 1706 Haedo, Provincia de Buenos Aires 1706
Argentina Argentina
Phone: +54 11 4650 8472 Phone: +54 11 4650 8472
Email: fgont@si6networks.com Email: fgont@si6networks.com
URI: http://www.si6networks.com URI: http://www.si6networks.com
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